In recent years, various adhesive patches and adhesive preparations have been developed. Adhesive preparation and adhesive preparation are highly superior in terms of protection of wound surface, continuous transdermal administration of a drug, drug metabolism by first-pass through the liver, and avoidance of various side effects.
In general, adhesive patches and adhesive preparations have a support made of a woven fabric, a non-woven fabric, a plastic film and the like and an adhesive layer laminated on the support, and are generally provided with a release liner laminated on the adhesive layer. They are provided in a package made of a packaging material such as a resin film and the like.
In such adhesive patches and adhesive preparations, the adhesive layer is required to have a certain thickness in consideration of the wound surface protection effect, and the effective drug content. However, when the adhesive layer becomes thick, the end of the adhesive patch and the like is easily rubbed against clothes and the like and turned up, as well as the components of the adhesive layer ooze or protrude from the end of the adhesive patch and the like, i.e., cold flow, thus posing problems during adhesion to the skin.
Cold flow occurs depending on the property of the adhesive layer. It often occurs when, in particular, an adhesive patch or adhesive preparation is under a load for a long time, that is, when an adhesive patch and the like are contained in a package and stored for a long period and the like.
Adverse effects of cold flow include, for example, difficulty in taking out an adhesive patch and the like from a package, which is caused by adhesion of oozed or protruded adhesive layer components to the inside of the package, turning and staining of adhesive patch and the like during adhesion to the skin, a lower medicinal effect of the adhesive preparation due to an outflow of the drug and the like. Therefore, adhesive patches and adhesive preparations desirably have an end not easily rubbed against clothes, do not permit easy cold flow, and have an adhesive layer retaining the original shape.
As a technique to handle such problem, JP-A-11-1432 (patent document 1) discloses an adhesive patch having a dry edge, which has a release liner extended from the end of a support and an adhesive layer. In such adhesive patch, oozing and protruding of an adhesive layer component from the end of an adhesive layer in contact with a release liner can be suppressed to some extent. However, in such adhesive patch, oozing and protruding of an adhesive layer component from the end of an adhesive layer in contact with a support may occur, and the preparation is not entirely satisfactory.
JP-A-6-63071 (patent document 2) discloses a covering material for wound (dressing material) which is contoured and has an adhesive layer fitting to the skin. In one example of this covering material for wound, the end is cut flatly, and therefore, oozing and protruding of an adhesive layer component from the end may occur, which results in the attachment of the component to the inner surface of the package.
In another example described in patent document 2, the end of the covering material is covered with a support. In such adhesive patch, however, the end of a support covers the end of an adhesive layer and, at the end of the adhesive patch, the end of the support aligns with the end of the release liner. Therefore, when in use, the release liner may not be easily detached from the end thereof with fingers. In addition, since the end of the support needs to be able to bend and cover the end of an adhesive layer, the degree of freedom of selection of the material and shape thereof, particularly thickness and the like, is low. Particularly, when the adhesive layer is thick, it is not easy to cover the end of the adhesive layer with the end of the support extended therefor in an industrial production stage. In fact, the thickness of the end of the adhesive layer of the adhesive patch in this example is molded to be thinner than that of the central part, and the thickness of the end of the adhesive layer is inferred to be difficult to maintain.